Successfully complete the indicated task to unlock the corresponding ending:

Ending 1: Do Not Complete Your Mission - At the end of Chapter 15, you will have the option to point the gun at Konrad or yourself through a mirror. If you point the gun at yourself, you will commit suicide and get the "A Farewell To Arms" trophy.

Ending 2: Surrender Yourself - Choose to shoot Konrad at the end of Chapter 15 to play the Epilogue. During the Epilogue, do not fire a shot at the soldiers arriving. Either give up your gun, or let them take it from you. You will get "The Road Back" trophy.

Ending 3: Die Fighting - Choose to shoot Konrad at the end of Chapter 15 to play the Epilogue. During the Epilogue, as the soldiers approach, open fire. You will die, but you will die fighting. You will get "The Road To Glory" trophy.

Ending 4: Freedom At Last - Choose to shoot Konrad at the end of Chapter 15 to play the Epilogue. During the Epilogue, kill all the incoming soldiers. This is very hard to accomplish. Once you kill all the soldiers, Walker will go free to do whatever he desires. You will not get an trophy for this ending.

Easy "The Road Back" and "The Road To Glory" trophies

Choose to shoot Konrad at the end of Chapter 15 to play the Epilogue. In the Epilogue, lay down your weapon when prompted to get the "The Road Back" trophy. Shoot the soldiers to get "The Road To Glory" trophy. You can reload the checkpoint after getting one trophy to make the other decision and get the other trophy.

Trophies

Successfully complete one of the following tasks to get a trophy:

Legion of Merit (Platinum): Unlock all trophies.

They Live (Bronze): What's lost is found.

Treacherous Ground (Bronze): Look out below.

The Lost Battalion (Bronze): We have contact.

Desert Storm (Bronze): Engineer an exit strategy.

The Horror (Bronze): Face the horrors of war.

Three Kings (Bronze): Stand united.

The Great Escape (Bronze): Get out of here!

A Bridge Too Far (Bronze): The end of the line.

A Man of Action (Bronze): Play it loose.

A Man of Patience (Bronze): Play it smart.

Damned if You Do (Bronze): Follow your orders.

Damned if You Don't (Bronze): Buck the chain of command.

Friendly Fire (Bronze): Show mercy.

Unfriendly Fire (Bronze): Save a bullet.

A Line, Crossed (Bronze): Choose vengeance.

A Line, Held (Bronze): Choose restraint.

A Farewell To Arms (Bronze): You are relieved.

Too Late The Hero (Bronze): Carry on, soldier.

The Road Back (Silver): Live and let live.

The Road To Glory (Silver): Live and let die.

Boot (Bronze): Complete game on "Walk on the Beach" difficulty.

We Were Soldiers (Silver): Complete game on "Combat Op" difficulty.

The Devil's Disciple (Gold): Complete game on "Suicide Mission" difficulty.